Nu-cyclopropyl, amides of 4-phenyl piperidino-alkanoic acids



United States Patent F 3,301,862 N-CYCLOPROPYL, AMIDES 0F 4-PHENYL PIPERIDINO-ALKANOIC ACIDS John H. Biel and Harvey B. Hopps, Milwaukee, Wis., assignors to Aldrich Chemical Company, Inc., Milwaukee, Wis., a corporation of Wisconsin No Drawing. Filed Apr. 7, 1964, Ser. No. 358,116 10 Claims. (Cl. 260293.4)

This invention relates to novel 4-arylpiperidines. More particularly, this invention relates to N-cyclopropyl amides of 4-phenylpiperidinoalkanoic acids and a process for the preparation thereof.

In accordance with the present invention, there is provided a member selected from the group consisting of 4-arylpiperidines of the formula an R8 and (III) R R (C nH2u) wherein n is a whole integer from 0 to 6 inclusive, and R and R are each a member selected from the group consisting of hydrogen, chloro, bromo, iodo, fluoro,

trifluoromethyl, amino, nitro, (lower)alkyl, (lower)- alkoxy, hydroxy, phenyl, phenoxy, benzyl, (lower)- alkylamino, di(lower)alkylamino, (lower)alkanoylamino, (lower)alkylthio, sulfamyl, (lower)alkanoyl, (lower)alkylsulfonyl, methylenedioxy, cycloalkyl radicals having from 5 to 7 carbon atoms inclusive and cycloalkoxy radicals having from 5 to 7 carbon atoms inclusive;

and the pharmaceutically acceptable nontoxic salts thereof.

3,301,862 Patented Jan. 31, 1967 hydrogen, chloro, bromo, iodo, fluoro, trifluoromethyl, nitro, (lower)alkyl, (lower)alkoxy, (lower)alkylthio, (lower)alkanoyl, phenyl, phenoxy and benzyl are preferred; preferably R or R and R or R are hydrogen and usually R R R and R are all hydrogen.

The pharmaceutically acceptable nontoxic salts include the organic and inorganic acid addition salts, e.g., those prepared from acids such as hydrochloric, sulfuric, sulfamic, tartaric, hydr-obromic, hydriodic, glycolic, citric, maleic, phosphoric, succinic, acetic and the like.

The term (lower)alkyl as used herein means both straight and branched chain aliphatic hydrocarbon radicals having from 1 to 8 carbon atoms such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, amyl, hexyl, Z-ethylhexyl, etc.

Similarly, where the term (lower) is used as part of the description of another group, e.g., (lower)alkoxy, it refers to the alkyl portion of such group which is therefore as described in connection with (lower)alkyl.

The meaning of the term (lower)alkylene is similar to that of (lower)alkyl in that it also means both straight and branched chain aliphatic hydrocarbon radicals having from 1 to 8 carbonatoms. Examples of (lower)alkylene radicals are methylene, ethylene, propylene, isopropylene, butylene, isobutylene, t-butylene, amylene, hexylene, 2-ethylhexylene and the like.

The compounds of this invention are valuable pharmaceutical agents. They exhibit antiarrhythmic activity which makes the compounds useful for the treatment of arrhythmia. In addition, the compounds, being tertiary bases, can be used to recover and purify penicillin with which they form salts.

Tests of the compounds of the present invention for antiarrhythmic activity were carried out by administering the compounds at dosages of 10 mgm./kg. intraperitoneally to experimental animals in which electrically induced ventricular fibrillation could be induced. Prevention of the ventribular fibrillation by a test compound, for example, N-2-phenylcyclopropyl-B-(4-hydroxy-4-phenylpiperidino)propionamide hydrochloride, indicates that the compound is an antiarrhythmic agent.

The compounds of the present invention are prepared by the following series of steps:

(1) A cyclopropylamine of the formula NHFQ wherein Z is as represented above is reacted with an equi- H molar quantity of a haloor tosyl acid chloride of the Among the radicals represented by R R R and R formula II A-Y-O-Cl wherein A is a radical selected from the group consisting of chloro, bromo, iodo ortosyl, and Y is as represented above according to the method described in US. Patent No. 2,569,288,

wherein A, Y and Z are as previously defined. The product, an N-cyclopropyl haloor tosylalkanoic acid amide, is a novel intermediate, useful in the second step of the method for the preparation of the 4-arylpiperidines of Formula I, and is considered within the scope of this invention.

(2) The N-cyclopropyl halo- 'or tosylalkanoic acid 3 amide prepared in step 1 is then reacted with an equimolar quantity of a piperidine of the formula wherein R and R are as described above, in the presence of triethyl amine and dimethylformamide, and a trace of potassium iodide at elevated temperature, i.e., 65 70 C., for several hours according to the procedure described in U.S. Patent No. 2,937,180. The cooled reaction mixture is then poured into water containing an equimolar amount of sodium hydroxide. The free base is collected by filtration and dried.

til-HQ wherein A, R R Y and Z are as defined above.

The free base may be readily converted, if desired, to a nontoxic acid addition salt by conventional procedures.

An alternate procedure for preparing the compounds of the invention comprises the addition of the secondary piperidine to an acrylic acid amide or a substituted acid lamide in the presence of -a strong base, e.g., sodium hydroxide, according to the equation wherein R R and Z are as represented above, and R and R are each hydrogen or (lower) alkyl.

A third procedure by which the compounds can be prepared involves the reaction of a haloor tosylalk'anoic acid ester with the secondary piperidine and subsequent conversion to the amide col and heated at 50100 C. for several hours in the presence of a base such as triethylamine, aminopyrine, diethylaniline, potassium carbonate and triethyl phenyl ammonium hydroxide. The cooled reaction mixture is then poured into dilute sodium hydroxide. The basic amide or ester precipitates either as a water-insoluble oil or a crystalline solid and is extracted with such solvents as methylene dichloride, chlorform, carbon tetrachloride or by filtration of the solid product. In the case of the third process, the ester that is obtained is reacted with cyclopropylamine, or a substituted cyclopropylamine, the product is then converted to a nontoxic acid addition salt.

It is obvious that in some cases, the radicals attached to the aromatic ring, e.g. the amino radical, will interfere with the reactions used in preparing the compounds of this invention. Therefore, it is necessary to block the reactive radicals before proceeding with the reactions. This is conveniently accomplished by methods known in the art. For example, in the ease of an amino substituted aromatic ring, the amino group is blocked by forming the Schitfs base by reacting the aromatic amine with an aldehyde such as acetaldehyde, and after all reactions have been completed, the Schiffs base may be cleaved with dilute hydrochloric acid to regenerate the free amino group.

The starting materials used in the processes described herein are compounds which are either commercially available, well-known in the prior art, or easily prepared in accordance with standard organic procedures previously described in the chemical literature.

The compounds of this invention may be administered as the free bases or in the form of their nontoxic addi- :tion salts. They may be compounded and formulated into pharmaceutical preparations for oral or parenteral administration with organic or inorganic solid materials or liquids which are pharmaceutically acceptable carriers,

The compositions may take the form of tablets, powder granules, capsules, suspensions, solutions and the like. Such compositions are considered within the scope of this invention.

The following examples are intended to illustrate the invention described herein without unduly restricting it.

Example ].Preparati0n of N-Z-phenylcyclopropyl-B- chloropropionamide To a slurry of 2-phenylcyclopropylamine (6.7 g., 0.05 mole) and Water (30 ml), cooled by means of an ice water bath to C., is added 3-chloropropionyl chloride (6.4 g., 0.05 mole) and a solution of sodium hydroxide (2 g., 0.05 mole) dissolved in Water (20 ml.). The rate of addition of the liquids is such as to keep the temperature below C. and the pH near 8. Upon completion of the addition, the mixture is stirred briefly, and permitted to stand overnight. The resulting solid is collected when dry, and weighs 6.25 g., M.P. 111-115 C. One recrystallization from benzene gives 5.5 g. of white solid, N-2-pheny1cyclopropyl-B-chloropropionarnide, M.P. 114-115 C.

Analysis.Calcd for C H CINO: C, 64.42; H, 6.31; N, 6.26; Cl, 15.85. Found: C, 64.93; H, 6.28; N, 6.47; Cl, 15.61.

' Example 2 When, in the procedure of Example 1, the 2-phenylcyclopropylamine is replaced by an equal molar amount of cyclopropyl-amine, Z-methylcyclopropylamine, Z-ethylcyclopropylamine, 2-isopropylcyclopropylamine, 2-phenylcyclopropylamine, 2 benzylcyclopropylamine, 2-1-naphthylcyclopropylamine, 2-2-naphthy-lcyclopropylamine, 2- 1-naphthylmethylcyclopropylamine, Z-pyridylcyclopropylamine, 2-3-thienylcyclopropylamine, 2-2 thienylcyclopropylarnine, 2-4-chlorophenylcyclopropylamine, 2-4-trifluoromethylphenylcyolopropylamine, 2-4-methylphenylcyclopropylamine, 2-2-fluorophenylcyclopropylamine, 2-3-methylphenylcyclopropylamine, 2-3-bromophenylcyclopropylamine, 2-4-hydroxyphenylcyclopropylamine, 2-2-methylaminophenylcyclopropylamine, 2-4-dimethylaminophenylcyclopropylamine, 2-2,6-dichlorophenylcyclopropylamine, 2-4-methylthiophenylcyclopropylamine, 2-2-sulfamylphenylcyclopropylaimine, 2-4-cyclohexylphenylcyclopropylamine, 2-4-cyclohexyloxyphenylcyclopropylamine, 2-4-nitrophenylcyclopropylamine, 2-2-aminophenylcyclopropylamine, 2-2-iodo-4-rnethylphenyleyclopropylamine, 2-4-isopropylphenylcyclopropylamine, 2-4-phenylphenylcyclopropylamine, 2-3-phenoxyphenylcyclopropylamine, 2-4-benzylphenylcyclopropylamine, 2-3-acetamidophenylcyclopropylamine, 2-4-acetylphenylcyclopropylamine, 2-2-ethylsulfonylphenylcyclopropylaminc, 2-3,4-methylenedioxyphenylcyclopropylamine, 2-4-fluorophenylcyclopropylamine, 2-4-chlorobenzylphenylcyclopropylamine, 2-1methyl-2-naphthylphenylcyclopropylamine, 2-2-chloro-1-naphthylrnethylphenylcyclopropylamine and 2-phenethylphenylcyclopropylamine, to produce oyclopropyl-fi-chloropropionamide, Z-methylcyclopropyl-fl-chloropropionamide, 2-ethylcyclopropyl-fl-chloropropionamide, 2-isopropylcyelopropyl-fi-chloropropionamide, 2-phenylcyclopropyl-fl-chloropropionamide,

2-benzylcyclopropyl-fl-chloropropionamide, 2-1-naphthylcyclopropyl-B-chloropropionamide, 2-2-naphthylcyclopropyl-fl-chloropropionamide, 2-l-naphthylmethylcyclopropyl-fl-chloropropionamide, 2-pyridylcyclopropyl-fi-chlor0propionamide, 2-3-thienylcyclopropyl-Bchloropropionamide, 2-2-thienylcyclopropyl- 3-chloropropionamide, 2-4-chlorophenylcyclopropyl-13-chloropropionamide, 2-4-trifluorornethylphenylcyclopropyl-B-chloropropionamide, 2-4-methylphenylcyclopropyl-fi-chloropropionamide, 2-2-fluorophenylcyclopropyl-fi-chloropropionamide, 2-3-methylphenylcyclopropyl-fl-chloropropionamide, 2-3-bromophenylcyclopropyl-B-chloropropionamide, 2-4-hydnoxyphenylcyclopropyl-fl-chloropropionamide, 2-Z-methylaminophenylcyclopropyl-fl-chloropropionamide, 2-4-dimethylaminophenylcyclopnopyl-B-chloropropionamide, 2-2,6-dichlorophenylcyclopropyl-fl-chloropropionamide, 2-4-methylthiophenylcyclopropyl-fl-chloropropionarnide, 2-2-sulfamylphenylcyc-lopropyl-B-chloropropionamide, 2-4-cyclohexylplienylcyclopropyl-B-chloropropionamide, 2-4-cyclohexyloxyphenylcyclopropyl-fi-chloropropionamide, 2-4-nitrophenylcyclopropyl-B-chlor-opropionamide, 2-2-a-minophenylcyclopropyl-fi-chloropropionamide, 2-2-iodo-4-methylphenylcyclopropyl-B-chloropropionamide, 2-4-isopropylphenylcyclopropyl-B-chloropropionamide, 2-4-phenylphenylcyclopropyl-[B-chloropropionamide, 2-3-phenoxyphenylcyclopropyl-{i-chloropropionamide, 2-4-benzylphenylcyclopropyl-fl-chloropropionamide, 2-3-acetamidophenylcyclopropyl-B-chloropropionamide, 2-4-acetylphenylcyclopropyl-B-chloropropionamide, 2-2-ethylsulfonylphenylcyclopropyl-B-chloropropionamide, 2-3,4-methylenedioxyphenylcyclopropyl-B-chloropropionamide, 2-4-fluorophenylcyclopropyl-B-chloropropionamide, 2-4-chlorobenzylphenylcyclopropyl-B-chloropropionamide, 2-1-methyl-2-naphthylphenylcyclopropyl-fl-ohloropropionamide, 2-2-ch'loro-1-naphthylmethylphenylcyclopropyl-fl-chloropropionamide, and Z-phenethylphenylcyclopropyl-B-chloropropionamide,

respectively.

Example 3 When, in the procedure of Example 1, the fi-chloropropionyl chloride is replaced by 0.05 mole of chloroacetyl chloride,

a-chloropropionyl chloride,

'y-chlorobutyryl chloride,

u-chloroisobutyryl chloride,

fi-bromopr-opionyl chloride,

18-i0dopropionyl chloride,

'y-chlorohexanoyl chloride and fi-tosylpropionyl chloride, respectively, the following compounds are produced,

N-2-phenylcyclopropyl-chloroacetamide,

N-2-pl1enylcyclopropyl-a-chloropropionamide,

N-Z-phenylcyclopropyl-v-chlorobutyramide,

N-Z-phenylcyclopropyl-a-chloroisobutyramide,

N-Z-phenylcyclopropyl-B-bromopropionamide,

N-Z-phenylcyclopropyl-B-iodopropionamide,

N-2-phenylcyclopropyl- -chlorohexanoamide, and

N-2-phenylcyclopropyl-fi-tosylpropionamide, respectively.

Example 4.Preparati0n of N-Z-phenylcyclopropyl-fi-(4- phenyl-4-hydr0xypiperidin0) propi onamide A mixture containing 0.05 mole of 4-phenyl-4hydroxypiperidine, 0.05 mole of N-Z-phenylcyclopropyl-B-chloropropionamide, 0.05 mole of triethylamine, 30 ml. of di- 1 1 wherein Y is a (lower)alkylene radical, Z is a member selected from the group consisting of hydrogen, (lower)alkyl, pyridyl, thienyl and radicals of I the formulae wherein n is a whole integer from to 6 inclusive,

R R R and R are each a member selected from the group consisting of hydrogen, chloro, bromo, iodo, fiuoro, trifluoromethyl, amino, nitro, (loweryalkyl, (lower) alkoxy, hydroxy, phenyl, phenoxy, benzyl, (lower) alkylamino, di(1ower) alkylamino, (lower) alkanoylamino, (lower)a1ky1thio, sulfamyl, (lower)- alkanoyl, (lower)alkylsulfonyl, methylenedioxy, cycloalkyl radicals having from 5 to 7 carbon atoms inclusive, and cyclo alkoxy radicals having from 5 to 7 carbon atoms inclusive, and

the pharmaceutically acceptable nontoxic salts thereof. 4. A compound selected from the group consisting of compounds of the formula 1 2 wherein Y is a (lower)alkylene radical, and the pharmaceutically acceptable nontoxic salts thereof.

5. A compound of the formula i ll omoHFoamQ 6. A compound of the formula 7. A compound of the formula (In Q 8. A compound of the formula I ll omom-o-mr 10. A compound of the formula 9. A compound of the formula C F3 5 OH OH N 0 CHgOHz(3NH Q No references cited.

WALTER. A. MODANCE, Primary Examiner.

AVROM D. SPEVACK, Assistant \Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION January "51, 1967 Patent No. 3,301,862

John H. Biel et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 7, lines 17 and 18, for "phenyl-4hydroxypiperidino propionamide hydrochlo-precipitates out, read pheny14- hydroxypiperidino) -propionamide hydrochloride precipitates out, line 64, for "N-Z-phenylcyclopropyl-B-[4-(4- ethylpheny1)4" read N-Z-phenylcyclopropyl-B-[4-(3- ch1oropheny1)4- line 72, for "N-Z-phenylcyclopropyl-B- [4-(3-methy1thiopheny1)4" read N-2-pheny1cyclopropyl-B- [4-(3-methy1phenyl) -4- column 8, line 1, for "N-Z- pheny1cyc1opropy16-[4-(3methy1pheny1)-4" read N-Z- phenylcyclopropyl6- [4-(3-methy1thiophenyl) -4- line 74, for "N-(2-3-trifluoromethylphenylcyclopropyl)" read N-(2-4- trifluoromethylphenylcyc'lopropyl) column 11, lines 6 to 13, the formula should appear as shown below instead of as. in the patent: 4

Signed and sealed this 17th day of October 1967 (SEAL) Attest:

EDWARD J. BRENNER EDWARD M.FLETCHER,JR.

Commissioner of Patents Attesting Officer 

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF COMPOUNDS OF THE FORMULA
 8. A COMPOUND OF THE FORMULA 